Livecheck Sentinel watch - 30-day URL condition watcher
Livecheck Sentinel watch - 30-day URL condition watcher. POST /v1/watch with {target, condition, callback, interval_s}. Detectors: status_change, keyword (same as /v1/check). HMAC-signed callbacks. Returns wtc_ id, owner_token (once), baseline, and a signed receipt. Fixed $2.50 USDC (2500000 atomic). GET/DELETE /v1/watch/{id} and GET /v1/watch/{id}/events with X-Livecheck-Owner-Token. No Playwright. Not /v1/check ($0.02) and not Confirm.
2500000 (raw units)
price
1
calls / 30d
1
unique payers
2026-09-10
updated
Provider
livecheck.fly.dev · discovered, not yet claimed by its owner
Payment (x402 accepts[])
[
{
"scheme": "exact",
"network": "eip155:8453",
"payTo": "0x33693228b706cb30f4b4dbf35f79129a763f91c5",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "2500000",
"maxTimeoutSeconds": 300
}
]Output schema
{
"bazaar": {
"info": {
"input": {
"body": {
"callback": {
"deliver": "on_change",
"secret": "whsec_example",
"url": "https://example.com/hooks/livecheck"
},
"condition": {
"detector": "status_change",
"params": {}
},
"interval_s": 900,
"target": {
"render": "never",
"selector": null,
"type": "url",
"url": "https://boards.greenhouse.io/example/jobs/1842"
}
},
"bodyType": "json",
"method": "POST",
"type": "http"
},
"output": {
"example": {
"baseline": {
"captured": true,
"hash": "cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc",
"summary": "live 2xx (200); apply form present, no closure banner"
},
"checks_remaining": 2880,
"condition": {
"detector": "status_change",
"params": {}
},
"expires_at": "2026-10-10T18:00:00Z",
"first_check_at": "2026-09-10T18:00:00Z",
"id": "wtc_01J8Z0K3N4P5Q6R7S8T9V0WWTC",
"interval_s": 900,
"next_check_at": "2026-09-10T18:15:00Z",
"owner_token": "owt_01J8Z0K3N4P5Q6R7S8T9V0WOWT",
"price_usd": 2.5,
"receipt": {
"hash": "eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee",
"verify_url": "https://livecheck.fly.dev/v1/receipt/wtc_01J8Z0K3N4P5Q6R7S8T9V0WWTC"
},
"run": "none",
"status": "active",
"target": {
"render": "never",
"selector": null,
"type": "url",
"url": "https://boards.greenhouse.io/example/jobs/1842"
},
"tier": "standard"
},
"type": "json"
}
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"callback": {
"description": "url + secret. deliver=on_change or every_check. HMAC-SHA256 over the raw JSON body (X-Sentinel-Signature).",
"type": "object"
},
"chain_budget_usd": {
"description": "Accepted and ignored in Phase 2. run stays none.",
"type": "number"
},
"condition": {
"description": "detector status_change or keyword. Same as POST /v1/check.",
"type": "object"
},
"context": {
"type": "object"
},
"interval_s": {
"description": "Seconds between observations. Min 300, default 900.",
"type": "number"
},
"label": {
"type": "string"
},
"target": {
"description": "URL target. type=url, render=never. render=always is 400 render_not_available.",
"type": "object"
}
},
"required": [
"target",
"condition",
"callback"
]
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"baseline": {
"properties": {
"captured": {
"type": "boolean"
},
"hash": {
"type": "string"
},
"summary": {
"type": "string"
}
},
"required": [
"captured"
],
"type": "object"
},
"checks_remaining": {
"type": "number"
},
"condition": {
"properties": {
"detector": {
"enum": [
"status_change",
"keyword"
],
"type": "string"
},
"params": {
"type": "object"
}
},
"required": [
"detector"
],
"type": "object"
},
"expires_at": {
"type": "string"
},
"first_check_at": {
"type": "string"
},
"id": {
"description": "Stable watcher id (wtc_ + ULID).",
"type": "string"
},
"interval_s": {
"type": "number"
},
"next_check_at": {
"type": "string"
},
"owner_token": {
"description": "Returned once on create. Send as X-Livecheck-Owner-Token.",
"type": "string"
},
"price_usd": {
"type": "number"
},
"receipt": {
"properties": {
"hash": {
"type": "string"
},
"signature": {
"type": "string"
},
"signer": {
"type": "string"
},
"verify_url": {
"type": "string"
}
},
"required": [
"hash",
"verify_url"
],
"type": "object"
},
"run": {
"enum": [
"none"
],
"type": "string"
},
"status": {
"enum": [
"active",
"stopped",
"expired"
],
"type": "string"
},
"target": {
"properties": {
"render": {
"enum": [
"never"
],
"type": "string"
},
"selector": {
"type": [
"string",
"null"
]
},
"type": {
"enum": [
"url"
],
"type": "string"
},
"url": {
"type": "string"
}
},
"required": [
"type",
"url",
"render"
],
"type": "object"
},
"tier": {
"enum": [
"standard"
],
"type": "string"
}
},
"required": [
"id",
"tier",
"owner_token",
"expires_at",
"checks_remaining",
"interval_s",
"first_check_at",
"baseline",
"price_usd",
"receipt"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}
}
}Use it
curl
curl "https://livecheck.fly.dev/v1/watch" # -> 402 Payment Required, accepts[] lists how to pay # retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid
JavaScript
const res = await fetch("https://livecheck.fly.dev/v1/watch");
if (res.status === 402) {
const { accepts } = await res.json();
// pay one of accepts[] via an x402 client, then retry with the payment header
}Python
import httpx
res = httpx.get("https://livecheck.fly.dev/v1/watch")
if res.status_code == 402:
accepts = res.json()["accepts"]
# pay one of accepts[] via an x402 client, then retry with the payment headerMachine-readable
Everything on this page is also available as clean JSON at /resources/12329.json, and this resource appears in /discovery/resources and /discovery/search.